Engine starter



June 29 ,1926 1,590,759

M. B. JACKSON ENGINE STARTER Filed June 2, 1925 INVENTDR Patented June 29, 1926;

MAUNSELL .B. JACKSON, .I'ORO'NTO, ONTARIO, CANADA.

ENGINE STARTER.

.Ap'plication med rune 2, 1925. Serial 1%. 34,490.

This invention relates to engine starters adapted to start internal combustion engines, and more particularly to that type in which a starter pinionis axially moved into and out of mesh with a gear on the engine. The pinion is normally out of mesh with the gear and when the starter isactuated the pinion is axially moved, due to inertia, into mesh with the gear. As soon as the engine is started the speed of the gear and thus the pinion is increased which causes the latter to be axially moved out of mesh With the gear. Heretofore it has been the general practice to provide an abutment for limiting the return movement of the pinion but the shock of the latter against the abutment is so great the pinion will rebound from the abutment and thus be fed again into engagement with the gear. The object of the present invention is to provide simple means to overcome this objectionable feature.

I attain my objectiby means of the constructions hereinafter described and illustrated in the accompanying drawings in which-- Fig. 1 is a side elevation of my starter showing the pinion and gear in mesh;

Fig. 2 a similar view' showing the pinion and gear out of mesh; and

Fig. 3 an end view of Fig. 2.

In the drawing like reference numerals indicate corresponding parts in the different figures.

An electric motor 1 (only partly shown) is provided with an extended armature shaft 2 having an end 3 of reduced diameter. On this end is secured, in any suitable manner, a collar 4. A projection 5 is carried at one side of the collar and is adapted to engage the convolutions of a helical spring 6 freely disposed on the shaft and collar.

One end of the spring is bent laterally to form a shoulder or a hook 7 which is normally free of or unconnected with the shaft or collar but is adapted to engage the projection 5 to form a rotary drive connection between the shaft and the spring. The other end of the spring is also bent to form a projection 8 to which is connected a start er pinion 9. The pinion is loosely or freely carried on the shaft 2 and the connection between the projection 8 and the pinion is formed by passing the projection into a notch or opening 10 formed in the flange 11 of a disk 12 secured to suitable manner.

the pinion in any The pinion is adapted to mesh with a gear 13 connected with the crankshaft of an engine (not shown) the common practice being to secure the gear to the engine flywheel.

The entering ends of the teeth of the pinion are also tapered ofl as shown to facilitate the meshing of these teeth with the teeth of the flywheel gear. 4

Assuming the starter mechanism is in its normal position as shown in Fig. 2 audit is desired to start the engine, the mode of oper ation is as follows. The motor 1 is energized which causes the shaft 2 and thus the collar 3 and the projection 5 to rotate. As hereinbefore mentioned the spring 6 and the pinion 9 are freely carried on the shaft 2 and the inertia of the former parts permits the shaft to rotate rel-ative to them. The projection. meshing with the convolutions of the spring, axially feeds or moves the latter and the pinion towards the gear. When the pinion has been axially moved a sufiicient distance to fully mesh it with the gear, the

to mesh it with the gear. Immediately the pinion meshes with the gear the latter prevents any tendency of the spring to rotate with the shaft until the hook'7 engages the projection 5. To ensure this engagement between the hook and the pin, I provide the following means. A shoulder forming an abutment 15 is adapted to engage one end of a spring 16 disposed on the shaft 2. The other end of this spring is adapted to engage the pinion to limit its inward movement. The spring 16 is much'lighter than the spring 6 so that it-may be compressed between the pinion and the abutment when the pinion is in mesh with the gear.

The pinion is returned to its inoperative position, when the engine is started, in the following manner. The speed of the flywheel gear when operated by the starter motor is less than its speed when the engine is started so that the instant the engine starts, the speed of the starter pinion, relative to the starter shaft, is increased. This causes the hook 7 to be disengaged from the pro ection 5 and permits the compressed spring 16 to axially move the pinion and sprin 6 on the shaft 2 until the end convolution of the springfi, on which the hook 7 is formed, will engage the outer side of the projection. The latter is then positioned between the convolutions of the spring 6 and the rotary movement of the latter, relative to the projection, will cause it to be threaded on the projection to move the pinion out of mesh with the gear.

It is obvious from the above description that a rebounding action of the spring from an abutment, for limiting its outward or return movement, would cause the spring to reverse its direction of rotation and feed the pinion towards the gear. To prevent this happening I provide the pinion with an inclined shoulder 17 formed on a laterally extending portion of the flange 11 and adapted to engage an inclined face 5 on the projection 5. Referring to Fig. 2 it will be noted that 'wedging action takes place when the inclined shoulder 17, which is being rotarily and axially moved relative to the inclined face 5* of the projection 5, strikes the face 5 This moves the shoulder 17 and thus the spring 6 axially on the shaft towards the gear 13 which causes the surface 6 on the spring 6 to bind against the adjacent side 5 of the projection 5. In other words the inclined shoulder 17 when it strikes the projection causes the direction of axial movement of the pinion 9 and spring 6 to be reversed whereby the latter frictionally engages the side of the projection to form a brake. This binding or breaking action prevents the rebound of the pinion and spring without permanently binding the latter parts with the projection. This is important as the projection must be free to draw away fromthe shoulder 17 when the starter motor is again energized.

It is to be distinctly understood that the word hook in the specification and claims means any type of projection or shoulder formed on or secured to the spring 6 for forming a driving connection between, the spring and the starter shaft wherebylithe former will be positively rotated by the latter. The word projection in the specification and claims means a pin or lug formed on or carried by the shaft.

What I claim is:

1. The combination with an internal combustion engine provided with a gear for revolving the crank shaft thereof, of starter mechanism including a shaft; a pinion freely carried on the shaft and normally out of mesh with the gear: a helical spring freely mounted on the shaft and having one end connected with the pinion; a projection carried by the shaft for engaging the con mechanism including a shaft; a pinion freely carried on the shaft and normally out of mesh with the gear; a helical spring freely mounted on the shaft and having one end connected with the pinion; a projection carried by the shaft for engaging the convolutions of the spring to actuate it axially on the shaft to thus move the pinion into and out of mesh with the gear, the projection being provided with an inclined face, the pinion being provided with an inclined shoulder. adapted to engage the said inclined face to draw the spring into engagement with the projection when the pinion is returning to its normal position.

3. The combination with an internal combusti-on engine provided with a gear for revolving the crank shaft thereof, of starter mechanism includin a'shaft; a pinion freely .carried'on the s aft and normally out of mesh with the gear; a helical spring freely mounted on the shaft and having one end connected with the pinion and provided at the opposite endwith a hook normally unconnected with the shaft; a projection carried by the shaft for engaging the convolutions of the spring to axially move the in-,

ion into mesh with the gear, the hook w en it has been axially moved by the projection being adapted to engage the latter to form a rotary drive connection between the shaft and the spring; and means for limiting the axial movement of the pinion in its normal position, the said means being adapted to cause the spring to bind on the projection.

4. The combination with an internal combustion engine provided with a gear for revolving the crank shaft thereof, of starter mechanism including a shaft; a pinion freely carried on the shaft and normally out of mesh with the gear; a helical spring freely mounted on the shaft and having one end connected with the pinion and provided at the opposite end with a hook normally unconnected with the shaft; a projection carried by the shaft for engaging the convolutions of the spring to axially move the pinion into mesh with the gear, the hook when it has been axially moved by the projection being adapted to engage the latter to form a rotary drive connection between the shaft and the spring, the projection being provided with an inclined face, the pinion being provided with an inclined shoulder volving the crank shaft thereof, of starter mechanism including a shaft; a pinion free- 1y carried on the shaft and normally out of mesh with the gear; a helical spring freely mounted on the shaft and having one end connected with the pinion and provided at the opposite end with a hook normally unconnected with the shaft; a projection carried by the shaft for engaging the convolutions of the spring to axially move the pinion into mesh with the gear, the hook when it has been axially moved by the projection being adapted to engage the latter to form a rotary drive connection between the shaft and the spring; an abutment; a spring engaging the abutment and tending to axially move the pinion out of mesh with the gear, the said spring being weaker than the first mentioned spring; and means for limiting the axial movement of the pinion in its normal position, the said means being adapted to cause the first mentioned spring to bind on the projection.

Signed at Toronto, Canada, this 9th day of May, 1925.

. MAUNSELL B. JACKSON. 

